Documentation

3 files changed, 32 insertions, 11 deletions

diff --git a/Makefile b/Makefile
index 62e0fb9d..a85a8076 100644
--- a/Makefile
+++ b/Makefile
@@ -1,19 +1,19 @@
 
-#PREFIX=/usr/local
+PREFIX=/usr
 CFLAGS=-O2 -Wall -g
 
 all: make-bcache probe-bcache
 
-clean:
-	rm -f make-bcache bcache-test *.o
-
 install: make-bcache probe-bcache
 	install -m0755 make-bcache ${PREFIX}/sbin/
-	install -m0755 probe-bcache ${PREFIX}/sbin/
+	install -m0755 probe-bcache /sbin/
 	install -m0644 61-bcache.rules /lib/udev/rules.d/
 	install -m0755 initramfs /usr/share/initramfs-tools/hooks/bcache
+	install -m0644 make-bcache.8 ${PREFIX}/share/man/man8
 #	install -m0755 bcache-test ${PREFIX}/sbin/
 
+clean:
+	rm -f make-bcache bcache-test *.o
 
 bcache-test: LDFLAGS += -lm -lssl -lcrypto
 make-bcache: LDFLAGS += -luuid
diff --git a/bcache.h b/bcache.h
index 448b6a50..0054f7d8 100644
--- a/bcache.h
+++ b/bcache.h
@@ -7,8 +7,9 @@ static const char bcache_magic[] = {
 
 struct cache_sb {
 	uint8_t		magic[16];
-#define CACHE_CLEAN	1
-#define CACHE_SYNC	2
+#define CACHE_CLEAN		1
+#define CACHE_SYNC		2
+#define CACHE_BACKING_DEVICE	4
 	uint32_t	version;
 	uint16_t	block_size;	/* sectors */
 	uint16_t	bucket_size;	/* sectors */
diff --git a/make-bcache.c b/make-bcache.c
index a7381d0a..9b9b0a17 100644
--- a/make-bcache.c
+++ b/make-bcache.c
@@ -4,6 +4,7 @@
 
 #include <fcntl.h>
 #include <linux/fs.h>
+#include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -58,21 +59,32 @@ long hatoi(const char *s)
 
 void usage()
 {
-	printf("");
+	printf("Usage: make-bcache [options] device\n"
+	       "	-C Format a cache device\n"
+	       "	-B Format a backing device\n"
+	       "	-b bucket size\n"
+	       "	-U UUID\n");
 	exit(EXIT_FAILURE);
 }
 
 int main(int argc, char **argv)
 {
-	int64_t nblocks, bucketsize = 32, blocksize = 8;
+	bool cache = false, backingdev = false;
+	int64_t nblocks, bucketsize = 0, blocksize = 8;
 	int fd, i, c;
 	struct cache_sb sb;
 	char uuid[40];
 
 	uuid_generate(sb.uuid);
 
-	while ((c = getopt(argc, argv, "U:b:")) != -1)
+	while ((c = getopt(argc, argv, "CBU:b:")) != -1)
 		switch (c) {
+		case 'C':
+			cache = true;
+			break;
+		case 'B':
+			backingdev = true;
+			break;
 		case 'b':
 			bucketsize = hatoi(optarg) / 512;
 			break;
@@ -84,6 +96,14 @@ int main(int argc, char **argv)
 			break;
 		}
 
+	if (!bucketsize)
+		bucketsize = cache ? 256 : 8192;
+
+	if (cache == backingdev) {
+		printf("Must specify one of -C or -B\n");
+		exit(EXIT_FAILURE);
+	}
+
 	if (argc <= optind) {
 		printf("Please supply a device\n");
 		exit(EXIT_FAILURE);
@@ -104,7 +124,7 @@ int main(int argc, char **argv)
 	}
 
 	memcpy(sb.magic, bcache_magic, 16);
-	sb.version = 0;
+	sb.version = backingdev ? CACHE_BACKING_DEVICE : 0;
 	sb.block_size = blocksize;
 	sb.bucket_size = bucketsize;
 	sb.nbuckets = nblocks / sb.bucket_size;